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          <h1 class="post-title" itemprop="name headline">Tomcat生产环境的性能调优</h1>
        

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        <blockquote>
<p>Tomcat生产环境的性能调优</p>
</blockquote>
<h4 id="背景"><a href="#背景" class="headerlink" title="背景"></a>背景</h4><p>java.lang.OutOfMemoryError: Java heap space —-JVM Heap（堆）溢出</p>
<p>工作时第一次遇见这个错误，很慌张因为客户那边网站无法访问了。出现的原因就是Tomcat配置的内存太小，访问量大的时候内存就溢出了。</p>
<p>天津项目考生查询会有短时间出现大量用户访问，这时就会有并发瓶颈。</p>
<h4 id="Tomcat性能优化一：内存的优化"><a href="#Tomcat性能优化一：内存的优化" class="headerlink" title="Tomcat性能优化一：内存的优化"></a>Tomcat性能优化一：内存的优化</h4><p>Tomcat默认可以使用的内存为128M o(╥﹏╥)o这点够干啥的！</p>
<p>在bin/catalina.bat或bin/catalina.sh 配置文件中进行。windows上，在catalina.bat中添加：</p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br></pre></td><td class="code"><pre><span class="line">set JAVA_OPTS=%JAVA_OPTS% -server -Xms1024m -Xmx1024m -XX:PermSize=<span class="number">256</span>M -XX:MaxNewSize=<span class="number">512</span>m -XX:MaxPermSize=<span class="number">256</span>m -Djava.awt.headless=<span class="keyword">true</span></span><br></pre></td></tr></table></figure>
<p>相关参数：</p>
<ul>
<li>JAVA_OPTS参数说明 <ul>
<li>-server 启用jdk 的 server 版； </li>
<li>-Xms java虚拟机初始化时的最小内存； </li>
<li>-Xmx java虚拟机可使用的最大内存； #-Xms与-Xmx设成一样的值，避免JVM因为频繁的GC导致性能大起大落</li>
<li>-XX:PermSize 内存永久保留区域 </li>
<li>-XX:MaxPermSize 内存最大永久保留区域</li>
<li>-XX:MaxNewSize 对自身堆栈的新的最大的分配；当tomcat内存不足时，调用此分配；</li>
<li>-Djava.awt.headless=true 这个参数下面单独解释↓↓↓
　　</li>
</ul>
</li>
<li>java.awt.headless 模式<ul>
<li>什么是 java.awt.headless？Headless模式是系统的一种配置模式。在该模式下，系统缺少了显示设备、键盘或鼠标。</li>
<li>何时使用和headless mode？Headless模式虽然不是我们愿意见到的，但事实上我们却常常需要在该模式下工作，尤其是服务器端程序开发者。因为服务器（如提供Web服务的主机）往往可能缺少前述设备，但又需要使用他们提供的功能，生成相应的数据，以提供给客户端（如浏览器所在的配有相关的显示设备、键盘和鼠标的主机）。</li>
<li>如何使用和Headless mode？<br>一般是在程序开始激活headless模式，告诉程序，现在你要工作在Headless  mode下，就不要指望硬件帮忙了，你得自力更生，依靠系统的计算能力模拟出这些特性来:<br>System.setProperty(“java.awt.headless”, “true”);</li>
<li>JAVA程序在浏览器中显示打印报表pdf文档时，报如下错误：<br>JasperReports encountered this error : Can’t connect to X11 window server using ‘:0.0’ as the value of the DISPLAY variable.<br>或者JasperReports encountered this error : sun/awt/X11GraphicsEnvironment</li>
<li>解决办法是<br>运行时加上-Djava.awt.headless=true</li>
</ul>
</li>
</ul>
<h4 id="Tomcat性能优化二：并发优化"><a href="#Tomcat性能优化二：并发优化" class="headerlink" title="Tomcat性能优化二：并发优化"></a>Tomcat性能优化二：并发优化</h4><p>1.调整连接器connector的并发处理能力，在Tomcat 配置文件 server.xml 中的</p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br></pre></td><td class="code"><pre><span class="line">&lt;Connector port=<span class="string">"9027"</span></span><br><span class="line">　　protocol=<span class="string">"HTTP/1.1"</span></span><br><span class="line">　　maxHttpHeaderSize=<span class="string">"8192"</span></span><br><span class="line">　　maxThreads=<span class="string">"1000"</span></span><br><span class="line">　　minSpareThreads=<span class="string">"100"</span></span><br><span class="line">　　maxSpareThreads=<span class="string">"1000"</span></span><br><span class="line">　　minProcessors=<span class="string">"100"</span></span><br><span class="line">　　maxProcessors=<span class="string">"1000"</span></span><br><span class="line">　　enableLookups=<span class="string">"false"</span></span><br><span class="line">　　URIEncoding=<span class="string">"utf-8"</span></span><br><span class="line">　　acceptCount=<span class="string">"1000"</span></span><br><span class="line">　　redirectPort=<span class="string">"8443"</span></span><br><span class="line">　　disableUploadTimeout=<span class="string">"true"</span>/&gt;</span><br></pre></td></tr></table></figure>
<ul>
<li>参数说明<ul>
<li>maxThreads 客户请求最大线程数 </li>
<li>minSpareThreads Tomcat初始化时创建的 socket 线程数 </li>
<li>maxSpareThreads Tomcat连接器的最大空闲 socket 线程数 </li>
<li>enableLookups 若设为true, 则支持域名解析，可把 ip 地址解析为主机名 </li>
<li>redirectPort 在需要基于安全通道的场合，把客户请求转发到基于SSL 的 redirectPort 端口 </li>
<li>acceptAccount 监听端口队列最大数，满了之后客户请求会被拒绝（不能小于maxSpareThreads ） </li>
<li>connectionTimeout 连接超时 </li>
<li>minProcessors 服务器创建时的最小处理线程数 </li>
<li>URIEncoding URL统一编码</li>
</ul>
</li>
</ul>
<p>2.Tomcat缓存优化</p>
<figure class="highlight java"><table><tr><td class="gutter"><pre><span class="line">1</span><br><span class="line">2</span><br><span class="line">3</span><br><span class="line">4</span><br><span class="line">5</span><br><span class="line">6</span><br><span class="line">7</span><br><span class="line">8</span><br><span class="line">9</span><br><span class="line">10</span><br><span class="line">11</span><br><span class="line">12</span><br><span class="line">13</span><br><span class="line">14</span><br><span class="line">15</span><br><span class="line">16</span><br><span class="line">17</span><br></pre></td><td class="code"><pre><span class="line">&lt;Connector port=<span class="string">"9027"</span></span><br><span class="line">　　protocol=<span class="string">"HTTP/1.1"</span></span><br><span class="line">　　maxHttpHeaderSize=<span class="string">"8192"</span></span><br><span class="line">　　maxThreads=<span class="string">"1000"</span></span><br><span class="line">　　minSpareThreads=<span class="string">"100"</span></span><br><span class="line">　　maxSpareThreads=<span class="string">"1000"</span></span><br><span class="line">　　minProcessors=<span class="string">"100"</span></span><br><span class="line">　　maxProcessors=<span class="string">"1000"</span></span><br><span class="line">　　enableLookups=<span class="string">"false"</span></span><br><span class="line">　　compression=<span class="string">"on"</span></span><br><span class="line">　　compressionMinSize=<span class="string">"2048"</span></span><br><span class="line">　　compressableMimeType=<span class="string">"text/html,text/xml,text/javascript,text/css,text/plain"</span></span><br><span class="line">　　connectionTimeout=<span class="string">"20000"</span></span><br><span class="line">　　URIEncoding=<span class="string">"utf-8"</span></span><br><span class="line">　　acceptCount=<span class="string">"1000"</span></span><br><span class="line">　　redirectPort=<span class="string">"8443"</span></span><br><span class="line">　　disableUploadTimeout=<span class="string">"true"</span>/&gt;</span><br></pre></td></tr></table></figure>
<ul>
<li>参数说明<ul>
<li>compression 打开压缩功能 </li>
<li>compressionMinSize 启用压缩的输出内容大小，这里面默认为2KB </li>
<li>compressableMimeType 压缩类型 </li>
<li>connectionTimeout 定义建立客户连接超时的时间. 如果为 -1, 表示不限制建立客户连接的时间</li>
</ul>
</li>
</ul>
<p>以上仅是工作中遇到的优化的方案，对应单一服务来说不管怎么优化总是有性能瓶颈的。 </p>

      
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<div class="my_post_copyright">
  <p><span>本文标题:</span>Tomcat生产环境的性能调优</p>
  <p><span>文章作者:</span>趙小傑~～</p>
  <p><span>发布时间:</span>2017年07月13日 - 15:34:33</p>
  <p><span>最后更新:</span>2019年07月13日 - 15:42:54</p>
  <p><span>原始链接:</span><a href="/2017/07/13/Tomcat生产环境的性能调优/" title="Tomcat生产环境的性能调优">https://cnsyear.com/2017/07/13/Tomcat生产环境的性能调优/</a>
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